Removably mountable arrow head and drill tap for making it

ABSTRACT

In a preferred embodiment, an arrow head base either a part of the arrow head or mountable thereon of an arrowhead, as the case may be, in which extending along a longitudinal axis from the base end mountable on an arrow shaft, is a conically shaped cavity having its inner walls converging to narrow cavity diameter toward the arrow head end of the arrow head base, and having helically extending paired ridge projections extending about radially inwardly from the converging converging inner walls, with a groove between paired projections and with each of paired projections leaning away from one-another overhanging adjacent inner wall surfaces, such that particularly steel arrow head bases so characterized are manually interchangeably mountable in a secure state not readily dislodged during normal use of the arrow, the process of producing such a steel arrow head base requiring a novel drill tap having helical threads extending along a substantially conical plane around the longitudinal axis of a tap shank of a plurality of sides as viewed in transverse cross-section, typically being substantially squared - such that upon drilling the cavity momentary screw-in rotary motion for predetermined duration of drilling motion, the plurality of shank wall extending angularly to one another forming pointed portions dig-out the groove portions during the forcefully axially moving screw-in and forms the arrow head base paired ridge projections leaning angularly in opposite directions, with the result that the ridge projections in effect act in the nature of barbs securing or secureable of the head in a mounted state on the end of particularly a wooden arrow shaft.

United States Patent [1 1 Frey, Jr. et al.

[451 Sept. 4, 1973 REMOVABLY MOUNTABLE ARROW HEAD AND DRILL TAP FORMAKING IT [76] Inventors: Edmund F. Frey, Jr., R.D. No. 1,

Pittstown, NJ. 08867; Clinton S. Grove, 44 Dogwood Way, Basking Ridge,NJ.

[22] Filed: July 27, 1972 21 Appl. No.: 275,194

Primary Examiner--Richard C. Pinkham Assistant Examiner--Paul E. ShapiroAttorney-William T. Hough [5 7 ABSTRACT In a preferred embodiment, anarrow head base either a part of the arrow head or mountable thereon ofan arrowhead, as the case may be, in which extending along alongitudinal axis from the base end mountable on an arrow shaft, is aconically shaped cavity having its inner walls converging to narrowcavity diameter toward the arrow head end of the arrow head base, andhaving helically extending paired ridge projections extending aboutradially inwardly from the converging converging inner walls, with agroove between paired projections and with each of paired projectionsleaning away from one-another overhanging adjacent inner wall sur faces,such that particularly steel arrow head bases so characterized aremanually interchangeably mountable in a secure state not readilydislodged during normal use of the arrow, the process of producing sucha steel arrow head base requiring a novel drill tap having helicalthreads extending along a substantially conical plane around thelongitudinal axis of a tap shank of a plurality of sides as viewed intransverse cross-section, typically being substantially squared suchthat upon drilling the cavity momentary'screw-in rotary motion forpredetermined duration of drilling motion, the plurality of shank wallextending angularly to one another forming pointed portions dig-out thegroove portions during the forcefully axially moving screw-in and formsthe arrow head base paired ridge projections leaning angularly inopposite directions, with the result that the ridge projections ineffect act in the nature of barbs securing or secureable of the head ina mounted state on the end of particularly a wooden arrow shaft.

'9 Claims, 7 Drawing Figures REMOVABLY MOUNTABLE ARROW HEAD AND DRILLTAP FOR MAKING IT This invention relates to an arrow head base as anintegral part of an arrow head or as a base section on which theseparate blade is interchangeably mountable, the invention relating tonovel threads by which the ferrule is mounted onto an arrow shaft.

BACKGROUND OF THE INVENTION Prior to the present invention, there haveexisted ferrules which are mounted or mountable removably onto thearrow-head end of an arrow shaft, and when such ferrules are plastic andthereby normally molded to shape, there has not been any major problemin obtaining diverse shapes which facilitate the secure mounting thereofonto the arrow shaft. However, the problem has been a major one withnonmoldable metals not subject to ready injection molding the jar ofimpact in particular causing such metal heads to come-off and possiblyto become lost. Consequently, it has been the general practice topermanently mount such heads or ferrules by a permanent mounting basesection or by a permanent arrow head base. As a result of thepermanently mounted practice heads, for example, being a part of arrowsof differing arrow head weight that of hunting arrows, the shooting ofhunting arrows is substantially different than that of the practicetarget arrows, thereby throwing-off the accuracy of the archer.

SUMMARY OF THE INVENTION Accordingly, an object of the present inventionis to obtain an arrow head base or a base ountable of a blade,overcoming one or more of the above type problems, together with othernovel advantages.

Another object is to obtain a base mounting thread (or threads)advantageous to both metal and plastic heads and/or ferrule(s). Y

Another object is a novel drill tap obtainable of the novel base threadsof the present invention particularly in the producing of metal targetand field point(s)'.

Other objects become apparent from the preceeding and followingdisclosure; 7 One or more of the objects of the present, invention areobtained by the invention as defined herein.

Broadly the invention includes the novel arrow head base or ferrulehaving a cavity defined by converging wall converging in the directionof the arrow-head blade end of the base, the converging inner-cavitywall having helically extending ridges extending at an acute angle overan adjacent face from which the ridge projection extends, and preferablybeing paired ridges helically continuous with a preferablyabout-V-shaped groove extending along between the ridge projections, andwith preferably the ridge projection in the paired state leaning inopposite directions from one-another.

As a result of the novel arrow head base(s) and/or ferrule(s) of thepresent invention, there are now provided heads or ferrules which are ofthe removably mountable nature of various unlimited types, particularlythe target points and field points being now also removably mountable.The arrow heads and/or ferrule(s) which incorporate the novel ridgeprojections of the present invention are removably mountable in a securestate, and are interchangle with hunting arrow heads. Additionally, thenormally light weight target heads may be now readily available in avariety of differing weights matching any of hunting heads and/or bladesof different weights, such that at any time of practice the archer maymount a head of a weight corresponding mass to that of the hunting head.

In arriving at the present invention, various ineffective processprocedures and drill taps were unsuccessfully tried before eventuallyarriving at the present invention arrow head base, inventive drill tap,and process utilizing that drill tap.

Basically the drill tap of the present invention must be atpredetermined force rammed into the conical cavity of a head to bedrilled, while concurrently turning the drill in a screw-in rotarydirection during the application of the ramming force, to result in thenovel arrow head base securing threads of the type already discussedabove. It should be noted that this process is primarily designed forand applicable to metal arrow head bases as opposed to plastic, sinceeven though some general plastics might successfully be drilled, it isnecessary for the plastic to which the process would be most beneficialin the resulting head, to be a plastic that is of high tensil strengthresistant to the breaking off of the ridge projections during the firstmounting or head removal operatin on an arrow shaft; typically a rigidor brittle plastic head would result in the shearing off of the ridgeprojection probably during the first use thereof. Also, if applied tothe drilling of plastic, because of the typically lesser tensilestrength thereof as compared to steel head base(s), the contour of theconverging outer walls of the novel drill tap and the amount of jammingforce and the bite of the helical drill tap threads must all varyslightly to best advantage in the drilling process and the resultingdurable head. The metal heads obtained by process and drill tap of thepresent invention are not subject to being produced by any other processnor any other drill tap.

Accordingly,'the novel drill tap must have helically extending along thelongitudinal axis thereof preferably a continuous thread whichpreferably rises to a point as viewed incross-section trasnverselyacross the body of the respective thread with thehelically extendingthread converging in a spiral'manner toward the insertion point of thedrill tap, while the drill tapsha'nk along the longitudinal axis of thedrill tap-also converges toward a point, but additionally with the shankwall surface between the drill tap threads including severalsubstantially flat faces meeting angularly one-another to form more orless corners, such that in a transverse cross-section through the shaftthere is viewed a multisided shank, preferably of about square shape,whereby during the process as above described the corner portionsgouge-out and force backwardly and/or forwardly gouged portions toresult in the ridge projections of the novel arrow headbase of thepresent invention.

The present invention may be better understood by reference to thefigures as follow.

FIG. 1 illustrates a side perspective view of a typical novel drill tapof the present invention.

FIG. 1A illustrates a typical transverse crosssectional view takenthrough the drill tap thread.

FIG. 2 illustrated a typical transverse cross-sectional view takenacross the longitudinal axis of the shank along lines 2-2 of the F IG. 1embodiment.

FIG. 3A illustrates a typical target arrow head having integral base asviewed in in-part cross-sectional side view through the conical cavityalready drilled by the novel process of the present invention.

FIG. 38 illustrates the same view as that of FIG. 3A, except that theFIG. 38 view is limited to an enlarged view of the portion within thesquare phantom-lines 3B of FIG. 3A.

FIG. 4A corresponds to the view of FIG. 3A except that this embodimentrepresent typical prior art for molded rerrule(s).

FIG. 4B similarly corresponds to the enlarged view of FIG. 38, thisprior art enlargement disclosing merely a helical perpendicularprojection relative to the face of the conical cavity inner surface ofthe ferrule wall.

DETAILED DESCRIPTION OF THE INVENTION In more particular reference tothe particular FIGS. reference is first made to FIG. 3A which disclosesthe typical said appearance of a novel arrow head embodying the novelsecuring threaded structure of the present invention, with therespectively bored portions 1 la and 11b of the phantomly outlinedsection 38.

In the enlarged view of FIG. 38, it is more discemably notable the verysmall bored portions 11a and 11b with the resulting oppositely leaningridge projections 13a and 1312 with the V-shaped groove therebetween. Inthis view there are viewable the two separate paired opposing sets ofridge projections, each set having its respective groove therebetween,such as the groove 12. It should be noted that these ridge projectionsare so small that they are scarcely viewable with the unaided eye, andthat the distance between consecutive rows of the re-occurringcontinuous helical ridge projections and grooves is very small.

Accordingly, it should be noted that the helical angle of progressionaxially per helical revolution of the helical thread around the shank inFIG. 1 is very small and that it is much smaller than that representedin the perspective view, the FIG. 1 accordingly not being to scale butbeing merely representative of the cutting and jamming blade-threads 7aand 7b along the conical portion of the tap 12 having tap shank faces 8,etc., extending around the shank and meeting to form cutting cornerportions such a corner 9 of the shank body 10 (FIG. 2). Like thespiraling threads 7a and7b converging helically to a lesser diameternearer the insertion portion, the shank body 10 similarly convergestowards a substantially pointed end 11. The tap is typicallh secureableby a suared section 13, or of any desired and/or conventional shapeemployable by a drilling machine.

As opposed to the above-described inventive arrow head base and drilltap and process, as illustrated in FIGS. 1, 2, 3A and 3B, the prior artclosest-structure to that of the present invention is illustrated by theFIGS. 4A and 4B which illustrate a molded plastic ferrule shown inpartial cross-section in FIG. 4A, with an enlarge view of the FIG. 4Aportion 43 illustrated FIG. 4B. In the prior art molded embodiment,there exist basically strictly upright (vertical) projections havingwide flat spaces between consecutive consecutive projections such as theprojection 14 having flat portions 15a and 15b adjacent opposite sidesof the projection 14. The molded helical continuous ridge verticalprojection is much more widely spaced and much more pronounced thanthose typically of the present invention also, although the presentinvention is not limited to specific dimensions, except that there arepreferred ranges for steel tap drilling which dimensions obviously wouldnot be the same for a plastic base to be drilled.

Typically the preferred drill tap has a shank which at its broaderdiameter is between about one-fourth inch and five-eighth inch,typically three-eighth inch in diameter, and the helical threads thereofpreferably taper at an angle ranging from about 3 to about 3, typicallyabout 5, at about 12 to 20 threads preferably per inch of taper,typically about 16 threads per inch. The height of the acute-angularlyleaning ridge projection above the inner wall surface over-hung by theleaning projection, is from about five to 15 ten-thousanths inch inheight for a steel base embodiment, and for the same steel base, thegulley or groove preferably ranges from about 10 to about 30ten-thousanths of an inch in depth. For plastic heads to be drilled, ormolded as the case may be, the plastic typically may be mylar type orany other suitable type that may be desired, as based on above-describedprerequisites.

The preceeding illustrative embodiments are intended to merelyillustrate the heart of the present invention, and not to limit thescope thereof. Thus, for example, any type or shape of arrow head orferrule or base may embody the present invention by the application ofordinary skill for modifications, variations, substitution ofequivalents, and the like, as within the scope and spirit of the presentinvention.

With regard to the embodiment illustrated in FIGS. 4A and 4B of theprior art, the illustrated structure is recognizable by those skilled inthe art as a ferrule mountable of a blade (not shown). As noted above,this type of ferrule as well as any other may embody the presentinvention, within the limitations as set forth as critically describedin the preceeding disclosure.

We claim:

1. A removably mountable arrow head base mountable on an arrow shaftsforward end, comprising in combination: an arrow head element having anaxially extending mounting base with a hollowed end of base walls havingan outer surface and having an inner surface with circularly opposingfaces defining a circular mouth and the opposing faces of the inner wallsurface converging from the mouth axially in an arrow-head end directionto an inner-cavity less in diameter than the diameter of said circularmouth, there being a plurality of ridge projections extending angularlyupwardly from said inner surface in a radially inwardwardly directionrelative to the circular nature of the inner surface converging from themouth, substantially each ridge projection defining an acute anglerelative to its respective base face, with the plurality of ridgeprojections extending in substantially common helical directions alongsaid converging inner wall surface.

2. A removably mountable head arrow head base mountable on an arrowshafts forward end, according to claim 1, in which each ridge projectionleans over said respective base face.

3. A removably mountable arrow head base mountable on an arrow shaftsforward end, according to claim 2, in which each ridge projectionconverges to substantially a point in side cross-section thereof.

4. A removably mountable arrow head base mountable on an arrow shaftsforward end, according to claim 3, in which the ridge projections arepaired and lean angularly in diverging axial directions from oneanotheralong said inner surface.

5. A removably mountable arrow head base mountable on an arrow shaftsforward end, according to claim 4, in which the space between each ofsaid diverging paired ridge projections is a substantially V- shapedgulley,

6. A removably mountable arrow head base mountable on an arrow shaftsforward end, according to claim 5, in which each of paired projectionsand the gulley therebetween is helically continuous with others of saidpaired projections and gulley thereof, of said plurality, and in whichsaid hollowed end is substantially of conical shape.

7. A removably mountable arrow head base mountable on an arrow shaftsforward end, according to claim 6, in which said base is of steel.

8. A removably mountable arror head base mountable on an arrow shaftsforward end, according to claim 1, in which said base is of steel.

9. A drill tap comprising an axially elongated member having a shankdefined by angularly converging outer shank walls convergingsubstantially axially to substantially a point, and including helicalsubstantially-axially extending thread projections projectingsubstantially radially outwardly from said shank, substantially eachhelical projection in cross-section having converging opposite surfacesrising to substantially a point, the tap shank in transversecross-section being defined by a plurality of substantially linearedges, each edge being angularly disposed with respect to the adjacentedge around the periphery of said shank, each adjacent piece of edgesdefining therebetween an outwardly directed vertex.

1. A removably mountable arrow head base mountable on an arrow shaft''sforward end, comprising in combination: an arrow head element having anaxially extending mounting base with a hollowed end of base walls havingan outer surface and having an inner surface with circularly opposingfaces defining a circular mouth and the opposing faces of the inner wallsurface converging from the mouth axially in an arrow-head end directionto an innercavity less in diameter than the diameter of said circularmouth, there being a plurality of ridge projections extending angularlyupwardly from said inner surface in a radially inwardwardly directionrelative to the circular nature of the inner surface converging from themouth, substantially each ridge projection defining an acute anglerelative to its respective base face, with the plurality of ridgeprojections extending in substantially common helical directions alongsaid converging inner wall surface.
 2. A removably mountable head arrowhead base mountable on an arrow shaft''s forward end, according to claim1, in which each ridge projection leans over said respective base face.3. A removably mountable arrow head base mountable on an arrow shaft''sforward end, according to claim 2, in which each ridge projectionconverges to substantially a point in side cross-section thereof.
 4. Aremovably mountable arrow head base mountable on an arrow shaft''sforward end, according to claim 3, in which the ridge projections arepaired and lean Angularly in diverging axial directions from one-anotheralong said inner surface.
 5. A removably mountable arrow head basemountable on an arrow shaft''s forward end, according to claim 4, inwhich the space between each of said diverging paired ridge projectionsis a substantially V-shaped gulley.
 6. A removably mountable arrow headbase mountable on an arrow shaft''s forward end, according to claim 5,in which each of paired projections and the gulley therebetween ishelically continuous with others of said paired projections and gulleythereof, of said plurality, and in which said hollowed end issubstantially of conical shape.
 7. A removably mountable arrow head basemountable on an arrow shaft''s forward end, according to claim 6, inwhich said base is of steel.
 8. A removably mountable arror head basemountable on an arrow shaft''s forward end, according to claim 1, inwhich said base is of steel.
 9. A drill tap comprising an axiallyelongated member having a shank defined by angularly converging outershank walls converging substantially axially to substantially a point,and including helical substantially-axially extending thread projectionsprojecting substantially radially outwardly from said shank,substantially each helical projection in cross-section having convergingopposite surfaces rising to substantially a point, the tap shank intransverse cross-section being defined by a plurality of substantiallylinear edges, each edge being angularly disposed with respect to theadjacent edge around the periphery of said shank, each adjacent piece ofedges defining therebetween an outwardly directed vertex.